Daniel Irimia's Biography

Daniel Irimia, MD, PhD is a biomedical engineer, trained as a physician, and pursuing research focused on the role of cell migration in health and disease conditions. At the interface between microscale-technologies and medicine, he is designing novel tools for precision measurements of white blood cell migration, for the early detection of sepsis in burn patients and for studying the mechanisms of inflammation resolution.

Autocatalytic Immune Reactions

Neutrophil swarms protect healthy tissues by sealing off sites of infection. During swarming, neutrophils accumulate fast and in large numbers, under the control of mediators released by neutrophils already at the site. These mediators stimulate the arrival of additional neutrophils in an autocatalytic reaction that results in an exponential rate of swarm size increase. However, despite the autocatalytic reaction, not all 25 billion neutrophils from one’s body end up in one giant swarm. Thus, our recent goal was to identify the physiologic mediators that disrupt the autocatalytic reaction and stop the growth of neutrophil swarms. For this, we developed and validated large microscale arrays of microbe clusters, which can trigger the synchronized growth of thousands of swarms at once. The new tool enabled us to concentrate large amounts of swarm-released mediators in small volumes, and ultimately identify lipoxin A4 (LXA4) is a key mediator that disrupts the autocatalytic reactions, stops the growth of swarms, and ultimately leads to swarm dispersal. These and other insights from the study of neutrophil swarming will teach us how to design better strategies to combat infections and to control acute and chronic inflammatory diseases.